How can we create goodwill value in the books of a firm which have goodwill in the market,but not having in book value?

First we have calculate the our total assets book value and after we are found the market value this different value is the goodwill value.
this is the as normal, Some company have lot of trad mark value but they can not explain his business when they are going to sales they are doing first they calculation of his total assets and they keeps some margin also than they found the goodwill but this condensation is depending on market and company position.

It is important to note that internally generated goodwill should not be included in the financial statements ! Only Purchased "acquired" positive /negative goodwill can be recorded.

Goodwill is recognised only if it is bought.

its quite easy calculate the value of Net Assets of a company and then deduct the Market value of comapny based on any method one of which is (EPS*P/E) then the differential amount would be the goodwill..